Commit 0fbf50b6 authored by Marcel Apfelbaum's avatar Marcel Apfelbaum Committed by Michael S. Tsirkin
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Revert "hw/pci: partially handle pci master abort" 



This reverts commit a53ae8e9.

The patch being reverted introduced a low-priority memory region
covering all 64 bit pci address space.  This exposed the following bugs
elsewhere in the code:
 1. Some memory regions have INT64_MAX size, where the
    intent was all 64 bit address space.
    This results in a sub-page region, should be UINT64_MAX.
 2. page table rendering in exec.c ignores physical address bits
    above TARGET_PHYS_ADDR_SPACE_BITS.
    Access outside this range (e.g. from device DMA, or gdb stub)
    ends up with a wrong region.  Registering a region outside this
    range leads to page table corruption.
 3. Some regions overlap PCI hole and have same priority.
    This only works as long as no device uses the overlapping address.

It doesn't look like we can resolve all issues in time for 1.7.
Let's fix the bugs first and apply afterwards for 1.8.

Signed-off-by: default avatarMarcel Apfelbaum <marcel.a@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent fe1479aa

hw/pci/pci.c

+0 −26
Original line number Diff line number Diff line
@@ -283,24 +283,6 @@ const char *pci_root_bus_path(PCIDevice *dev) 
    return rootbus->qbus.name;

}



static uint64_t master_abort_mem_read(void *opaque, hwaddr addr, unsigned size)

{

   return -1ULL;

}



static void master_abort_mem_write(void *opaque, hwaddr addr, uint64_t val,

                                   unsigned size)

{

}



static const MemoryRegionOps master_abort_mem_ops = {

    .read = master_abort_mem_read,

    .write = master_abort_mem_write,

    .endianness = DEVICE_LITTLE_ENDIAN,

};



#define MASTER_ABORT_MEM_PRIORITY INT_MIN



static void pci_bus_init(PCIBus *bus, DeviceState *parent,

                         const char *name,

                         MemoryRegion *address_space_mem,
@@ -312,14 +294,6 @@ static void pci_bus_init(PCIBus *bus, DeviceState *parent, 
    bus->address_space_mem = address_space_mem;

    bus->address_space_io = address_space_io;





    memory_region_init_io(&bus->master_abort_mem, OBJECT(bus),

                          &master_abort_mem_ops, bus, "pci-master-abort",

                          memory_region_size(bus->address_space_mem));

    memory_region_add_subregion_overlap(bus->address_space_mem,

                                        0, &bus->master_abort_mem,

                                        MASTER_ABORT_MEM_PRIORITY);



    /* host bridge */

    QLIST_INIT(&bus->child);

include/hw/pci/pci_bus.h

+0 −1
Original line number Diff line number Diff line
@@ -23,7 +23,6 @@ struct PCIBus { 
    PCIDevice *parent_dev;

    MemoryRegion *address_space_mem;

    MemoryRegion *address_space_io;

    MemoryRegion master_abort_mem;



    QLIST_HEAD(, PCIBus) child; /* this will be replaced by qdev later */

    QLIST_ENTRY(PCIBus) sibling;/* this will be replaced by qdev later */